Suspension-type file folders generally comprise a pair of leaves hinged together at their bottom, e.g. at a fold, and are provided at their upper edges with laterally extending hooks adapted to overhang and rest upon rails in a file drawer or cabinet. The hooks of each leaf may be unitary with a metallic strip or bar running the full length of the upper edge of the leaf.
The file folders are commonly formed of cardboard, paperboard or like relatively stiff material and can be provided along a horizontal upper edge or a vertical lateral edge with indicia representing the contents of the file, its classification or order in a system of classification, or like means readable by the user.
For example, an indicating tab can be mounted on the file folder and can form, or be formed with a transparent window into which an identifying label can be removably inserted.
It is also known to provide such suspension file folders with means, associated with the indicating tab or otherwise, for connecting successive files together, e.g. by providing one leaf of one folder with a male member and the proximal leaf of the next folder with a female member, the two members mating to interconnect the folders and form an accordion-like arrangement from a multiplicity of folders thereby preventing the introduction of documents or other articles between successive folders.
In general, there are two types of connections which are used in association with the indicating tab or can be considered connected or part thereof for the purposes of interconnecting successive folders.
The first of these arrangements makes use of a tab formed with lips directed rearwardly and forming a seat engageable with an edge of the proximal leaf of the next file.
The second and more common connecting arrangement is of a snap fastener or pushbutton type in which the male members are fixed on one edge of the file folder, while the female members are rigid with the indicating tab fixed on the corresponding edge of the next file.
This second type has predominated in the past because its use is more convenient, the system is relatively compact and neat, and mounting and dismounting an assembly of files in a given classification system is facilitated.
However, notwithstanding the significant advantages of this arrangement, there are certain disadvantages.
For example, the indexing or identifying tab must be composed of two different materials, at least insofar as the present developments of synthetic resins are concerned. The sheath or window containing the replaceable label usually must be highly transparent, a characteristic readily attainable with the somewhat more rigid synthetic resins, while the female member must be composed of a material capable of a high degree of resilient flexure, which is a characteristic usually not present in the synthetic resins having a high degree of transparency.
Thus the parts which are required to be more supple and flexible are customarily made from synthetic resin materials quite different from those forming the transparent element or window of the tab.
Not only does this increase the cost of manufacture and complicate fabrication, but it also creates problems with respect to structural integrity and mounting upon the file folder.